Study of olivines from Omolon and Seymchan meteorites using X-ray diffraction and Mössbauer spectroscopy with a high velocity resolution

Abstract

Articles you may be interested inStudy of Chelyabinsk LL5 meteorite fragment with a light lithology and its fusion crust using Mössbauer spectroscopy with a high velocity resolution AIP Conf. Proc. 1622, 24 (2014) Abstract. Study of olivine from Omolon and Seymchan meteorites was performed using X-ray diffraction and Mössbauer spectroscopy with a high velocity resolution. X-ray diffraction patterns were measured at room temperature while Mössbauer spectra were measured at 295 and 90 K. The orthorhombic crystal lattice parameters were evaluated for olivine from Omolon and Seymchan. These parameters appeared to be different for olivines from both meteorites. Mössbauer spectral components related to 57 Fe in crystallographically non-equivalent sites M1 and M2 in both olivines were determined and its Mössbauer hyperfine parameters were evaluated. Some differences in the tendencies of temperature dependence of spectral parameters and small variations of 57 Fe quadrupole splitting in both M1 and M2 sites of olivines from Omolon and Seymchan were found. On the basis of Mössbauer parameters and chemical data, the temperatures of equilibrium cation distribution were evaluated for both olivines.

Applications of Mössbauer Spectroscopy in Meteoritical and Planetary Science, Part II: Differentiated Meteorites, Moon, and Mars

“…The same calculations for the 90 K olivine Mössbauer data demonstrated K D = 1.29, T eq = 997 K for Omolon and K D = 1.31, T eq = 938 K for Seymchan. The results calculated for the 90 K Mössbauer spectra were considered the most reliable [39]. It was noteworthy that the ∆E Q values for the 57 Fe in both M1 and M2 sites were slightly different for olivines extracted from Omolon and Seymchan PMG meteorites at 295 K and at 90 K. This result indicates that the 57 Fe local microenvironments in the M1 sites and in the M2 sites in the two olivines were slightly different.…”

“…The first study of olivine extracted from Omolon PMG and Seymchan PMG using Mössbauer spectroscopy with a high velocity resolution was performed in [38][39][40]. The Mössbauer spectra of olivine separates from both pallasites measured at 295 and 90 K are shown in Figure 16.…”